The present invention relates to split type seat back composing a seat for a vehicle. More particularly, the present invention relates to a split type seat back having a plurality of seat backs which are attached to a floor of the vehicle, arranged in the vehicle width direction and capable of independently moving with each other.
In a split type seat back for a vehicle, an outer end portion and an inner end portion in the vehicle width direction of each seat back are pivotally attached onto a vehicle body floor through a floor bracket and a center hinge bracket so that the each seat back can be independently moved with each other.
In this connection, in a case where a seat provided with such a split type seat back is a rear seat used for a wagon and no bulkhead is provided between the rear seat and a luggage compartment located behind the rear seat, the following problems may be encountered. At the time of sudden braking operation, luggage loaded in the luggage compartment is moved forward by the effect of inertia and collides with the seat backs. Then, an impact load is given being concentrated onto the center hinge brackets by the moving luggage. Therefore, the center hinge brackets are damaged. As a result, the right and left seat backs are opened like a double door and a resin cover to cover each center hinge bracket is disconnected.
Accordingly, Patent Document 1 proposes the following constitution. In a case where a load is given to the seat backs from the luggage compartment, right and left hinge portions engaged with the other side edge of the other seat back are provided in the center hinge brackets.
Patent document 1: Japanese Patent Publication No. 11-208336A
However, in the constitution proposed in the Patent Document 1, the following problems may be encountered. According to the form of deformation of the center hinge brackets, there is a possibility that teeth of the engaging portions of the hinge portions are not engaged with each other. Accordingly, they feel uncertain about the reliability. Further, machining of the engaging portions is complicated. Furthermore, a highly accurate machining is required. Therefore, the manufacture of the center hinge brackets is difficult.